Meeting Abstract

P1.206  Friday, Jan. 4  Reconstruction of the flight characteristics of winged seeds of Late Paleozoic conifers STEVENSON, RA*; EVANGELISTA, D; LOOY, CV; University of California, Berkeley; University of California, Berkeley; University of California, Berkeley rstevenson.cal@berkeley.edu

Fossil seeds of a voltzian conifer from the late Early Permian (~270 million years ago) in north-central Texas, are the earliest known conifers that produce samaras (winged seeds). Extant conifers predominantly produce single winged samaras. The cone scales of this early voltzian conifer are exceptional in that they produce a range of winged-seed morphotypes. They bear either one or two wings on the chalazal end of the seed, with the second wing ranging in size from a stub to a wing equal in size to that of the primary wing. To examine the aerodynamics of the different wing types and their implications on dispersal potential, we present the flight performance of 1:1 scale models of the geometric morphometric consensus of three morphotypes of the samaras. To test the validity of such modeling as an inferential tool, descent of model samaras was captured with high speed video. The flight characteristics were compared to morphologically similar samaras of extant Agathis taxa as well as similarly created Agathis models. Based on our model observations, we infer ranges of descent speeds, auto-rotational stability, possible descent patterns, and dispersal potentials for the voltzian seeds. Reconstruction of these early forms of seed flight provides insight into why the single winged samaras are prevalent in extant taxa. Winged seeds may be used as proxy for minimum height in Late Paleozoic conifers.